1. Technical Field
The present invention relates to an emissive device including light-emitting elements, such as organic light-emitting diodes, which emit light having a luminance level corresponding to a current, and relates to an electronic apparatus including the emissive device.
2. Related Art
Electroluminescent (EL) elements that are excited by an electric field to emit light are one known example of light-emitting elements. In an emissive device including EL elements, many pixel circuits are arrayed in a matrix on a substrate, and one of the EL elements is disposed in each pixel circuit. Each EL element has a light-emitting layer disposed between an anode and a cathode. A hole injection layer or other layer is disposed between the anode and the cathode, in some cases.
An example of such an emissive device is of the top emission type, in which light emitted from an EL element emerges from a side opposite a substrate, as described in Japanese Unexamined Patent Application Publication No. 2003-288983 (Patent Document 1) and the like. Furthermore, Patent Document 1 also discloses a light-shielding layer as black matrix opposite the substrate. The light-shielding layer has light-transmitting portions. Light emitted from each EL element emerges through the corresponding light-transmitting portion. Each light-transmitting portion has a color filter. Moreover, Patent Document 1 discloses a partition composed of an insulating material and disposed on the substrate to partition the light-emitting elements. Openings in the partition demarcate light-emitting regions of the light-emitting elements. That is, pixel electrodes are in contact with the light-emitting layers or hole injection layers in the openings in the partition. When a current flows between the pixel electrodes and opposite electrodes, the light-emitting layers disposed in the opening emit light.
Each light-transmitting portion of the light-shielding layer disclosed in Patent Document 1 is wider than the corresponding opening in the partition. It seems that this structure is employed so as to maximize the radiation of pencils of light emitted from the light-emitting regions, which correspond to the openings in the partition, of the light-emitting elements to the outside. In this structure, the pencils of light viewable from the outside are regulated by the openings in the partition.
The light-emitting layers and the hole injection layers of the emissive device have high adhesion to the pixel electrodes but low adhesion to the partition. Thus, each of the light-emitting layers or each of the hole injection layers may have nonuniform thickness in the corresponding opening in the partition. Furthermore, in some cases, each light-emitting layer or each hole injection layer does not adhere to the corresponding pixel electrode in the vicinity of the partition. In these cases, luminance and chromaticity disadvantageously vary in a single pixel. Specifically, luminance and chromaticity at the peripheral portion close to the partition in each pixel may differ from those at the middle portion remote from the partition in the same pixel. In the art described in Patent Document 1, since the light-transmitting portion of each light-shielding layer is wider than the corresponding opening in the partition, non-uniformity in luminance and chromaticity in a single pixel may be visually identified.
Furthermore, in the art described in Patent Document 1, since the light-transmitting portion of each light-shielding layer is wider than the corresponding opening in the partition, pencils of light coming through the light-transmitting portion of each light-shielding layer and then radiating to the outside diverge at a large solid angle. When the emissive device is used as an image display, the divergence of the pencils of light may affect viewability. When the emissive device is used as an exposure device that is required to have high accuracy, the excess divergence of the pencils of light adversely affects accuracy.